Chapter XV

S. W. WINDS. _After a northerly Wind for the most Part two months
or more, and then coming South, there are usually_
three or four fair Days at first, and then, on the fourth
or fifth Day, comes Rain, _or else the Wind turns North
again_, and continues dry.

THIS is likewise a very judicious and very useful Observation, and yet it is not a difficult matter to account for it. It is a common Observation, and a very true one, that there is usually fair Weather before a settled course of Rain. The Winds that bring the dark rainy Clouds that obscure the Sky, and cause dull cloudy Weather, often raise these Vapours to such a height, that they are attracted into the cold Region above our Sight, till being condensed there, they fall down upon us again in Snow or Rain, according to our Author's Observation.

BUT if, after a seeming Tendency to Rain, there follow several Days of fine Weather, it is a certain Indication that the Temper of the Air is altered, and that these Vapours had been driven off before they had time to condense, which is confirmed by the Change of the Wind on such Occasions.

ALL these Observations are to be understood in a proper Latitude, and not strictly and according to the very Letter. For Rain may fall the sixth or seventh Day, or the Wind may change the second or third. Besides, a Man who would make use of these Observations in the Country, must consider attentively the Situation of the Place where he lives, the bearing of the Sea, Marshes, Ponds, Lakes, Woods, Mountains, Rocks, _&c._ For without making proper Allowances for these, all such Observations on the Weather will be apt to fail him.